Pennsville Township is a township in Salem County, in the U.S. state of New Jersey. As of the 2010 United States Census, the township's population was 13,409, reflecting an increase of 215 (+1.6%) from the 13,194 counted in the 2000 Census, which had in turn declined by 600 (-4.3%) from the 13,794 counted in the 1990 Census. The township is named for William Penn. The township includes the state's westernmost point.